Your GP will usually carry out a physical examination. They'll look at your anus and the surrounding area to check for damage and carry out a rectal examination, inserting a gloved finger into your bottom.

A rectal examination will show whether constipation is the cause, and check for any tumours in your rectum. Your GP may ask you to squeeze your rectum around their finger to assess how well the muscles in your anus are working.

Depending on the results, your GP may refer you for further tests.

Further tests

Endoscopy (sigmoidoscopy)

During an endoscopy, the inside of your rectum (and in some cases your lower bowel) is examined using a long, thin flexible tube with a light and video camera at the end (endoscope). Images can also be taken of the inside of your body.

The endoscope checks whether there's any obstruction, damage or inflammation in your rectum.

An endoscopy isn't painful, but it can feel uncomfortable, so you may be given a sedative to relax you.

Anal manometry

Anal manometry helps to assess how well the muscles and nerves in and around your rectum are working.

The test uses a device that looks like a small thermometer with a balloon attached to the end. It's inserted into your rectum and the balloon is inflated. It may feel unusual, but it's not uncomfortable or painful.

The device is attached to a machine, which measures pressure readings taken from the balloon.

You'll be asked to squeeze, relax and push your rectum muscles at certain times. You may also be asked to push the balloon out of your rectum in the same way you push out a stool. The pressure-measuring machine gives an idea of how well your muscles are working.

If the balloon is inflated to a relatively large size but you don't feel any sensation of fullness, it may mean there are problems with the nerves in your rectum.

Ultrasound

An ultrasound scan can be used to create a detailed picture of the inside of your anus. Ultrasound scans are particularly useful in detecting underlying damage to the sphincter muscles.

Defecography

Defecography is a test used to study how you pass stools. It can also be useful in detecting signs of obstruction or prolapse that haven't been discovered during a rectal examination.

During this test, a liquid called barium is placed into your rectum. The barium helps make it easier to highlight problems using an X-ray. Once the barium is in place, you'll be asked to pass stools in the usual way while scans are taken.